One-piece roller bearing cage



Oct. 27, 1953 L. R. LovELL ET AL 2,657,106

ONE-PIECE ROLLER BEARING CAGE Filed April 25 1951 Patented Oct. 27, 1953ONE-PIEGE ROLLER BEARING CAGE Louis B. Lovell and James E. West, Jr.,Philadelphia, 2a., assignors to SKF Industries, Inc., Philadelphia, Pa.,a corporation of Delaware Application April 25 1951; Serial No. 222,864

3 Claims.

This invention relates to a one-piece cage for roller bearings havingpockets arranged for radial insertion of rollers into one end and. theirretention on the opposite end by tangs. whose ends project partiallyacross the pocket area to form obstructions.

An. object of the invention is to provide for enicient assembly ofroller bearings having onepiece cages.

Another object is to provide an obstruction overlapping the roller cage:pocket by a novel method employing. only the well-knowndrilling andbreaching operations now used to produce pocketsv of rectangular form,and to limit movement of. the rollers by such obstructions.

Another object is to save the cost of separatebending operations for thepocket-obstructing.

tangs as. now required in present-day one-piece roller cages.

Fig. 1 is a face view partly in section oi a roller bearing equippedwith a roller cage made in accordance with the invention;

Fig. 2. is. an enlarged sectional view taken along line 2-1 of Fig. l; i

Fig. 3 is a fragmentary enlarged-sectional view of the roller bearingcage illustrating the position. of the rollers in the cage ina primarystage of assembly;

Fig. 4 isa. top. plan view of the. fragment. of. the cage shown in Fig-3 but without the rollers;

Fig. 5;. is. an. enlarged fragmentary sectional perspective view of. theroller bearing cage showing. certain structural, details;

Fig. 6 is av fragmentary sectional perspective view of the annular blankfrom. which the cage is produced;

Fig. 7 is a fragmentary sectional view showing an initial operationinforming one of the. roller pockets, and

Fig. 8 is a fragmentary plan view illustrating a subsequent breachingoperation in the pocketiorming process.

In producing one-piece cases of the type to which the-present inventionrelates, it has been customary first to drill a hole for each rollerradially through the outer peripheral surface of an annular blank andtheir to square these round holes by broaching, the breach. preferablybeing passed simultaneously through two opposite pockets. Use of an oddnumber of rollers is avoided as fares possible. Toassemblethe bearingthe one-piece cage: thus produced is placed inside the fiangesici an.outer raceringor' out side the flangesiofr: an inner race. ring, and therollers are then inserted" into. tl'ieipockets r and the race groove. Inthis operation the race ring is laid flat on its face horizontallytokeep rollers from fallin out. In this position the rollers standupright on their ends. Roller bearing cages of this type have been usedin industry intens of thousands, particularly inv aircraft where theyofier the weight-saving advantages of light metal alloys. The cages haveproven very satisfactory in service.

Much annoyance has been experienced, however, when disassembling thebearings for in spection, because of the fact that the rollersfrequently fall out oftheir pockets and become dirty or get lost. Toavoid this difficulty fingers were added projecting radially from sideWalls of pockets, inwardly or outwardly in accordance with which of therace ringscarried. the roller retaining. flanges, and. the ends of thesefingers were bent a short distance across the pocket spaces so as toprevent the rollers from falling from the obstructed ends of thepockets. In a bearing having race rings of. the torm shown in Fig. 2,.for example, wherein disassembly requires removal first of the innersingle-flanged race rings, the fingers. would; be placed at the innerperiphery of the. cage, so that when the inner race ring. has been.withdrawn. the rollers would still be retained. in the cage pockets.Rollers will not readily fall. out of a cage kept fiat in. horizontalposition with both races removed so long as the rollers are kept inpositions close to the obstructions. One-piece roller cages so equippedare desirable but addmaterially to costs because of the additional.machining and. labor required to bend. obstructions to operativeroller-retaining positions. In many instances multiple bendingoperations are required. For some forms of bearing the: ends. on thefingers. are necessarily thin, while for others the ends are thick. Somethin ends. prove too weak to keep rollers. in position; and most of thethick ends crack or break otf entirely in the bending, operation. Thisinvention eliminates. both of these difiicultiesa The present. inventionprovides a method for forming fingers on the side walls of thepockets,whose ends form tangs whichwill obstruct the pocket spacessufiici'en-tlyto accomplish: retention of the rollers, said methodinvolving use only of a. drill and a breach as in. the productionoforiginal one-piece fingerless roller cages. The invention provides:thoroughly satisfactory cages of improved characteristics atconsiderably reduced costs. 1 l r The invention will bemore readilyunderstood by reference to Figs; I and-2 show-archer best illustrated inFig. 4.

bearing having a cage constructed in accordance with our novelprinciple. The bearing comprises an outer race ring H1, an inner racering M, and the aforesaid cage l6 having pockets for the plurality ofrollers 53. In the present instance, the outer ring 16 is formed withaxially spaced inner flanges l I, I i which form therebetween a race I2for the said rollers. The inner ring M is formed in the present instancewith an outwardly projecting flange i5 which defines one side of theinner rin roller race. In some installations the flange I5 may beomitted. The cage it which lies between the rings consists of an annularbody member containing a plurality of circumferentially spaced generallyrectangular radial pockets l1 separated by crossbars l8 and bounded atthe sides by the annular side portions l9 and 26, as The pockets i?receive the rollers as previously set forth, and in the assembledbearing the cage rides on the fianges H of the outer race ring, as shownin Figs. 1 and 2, and retains the rollers in properly spaced and alignedpositions between the rings. The cage H5 is made in one piece, and eachof the crossbars [*8 has a radially projecting central finger 2! theextremity of which is offset circumferentially of the cage for a purposenow to be described.

In assembling the bearing, the cage It is laid flat on the assemblytable, and the individual rollers [3 are then inserted into the pocketsll from the outer ends thereof, the rollers being moved inwardly untilstopped by the offsetse at the inner ends of the fingers 2!, the rollersthen occupying the positions shown in Fig. 3. In this position therollers lie within or project only slightly beyond the outer peripheralsurface of the cage which is of lesser diameter than the innerperipheries of the outer ring flanges ll, so that the ring In may beplaced around the cage and roller assembly on the table. The rollers arethen displaced radially outwardly into the race l2 of the ring It, asshown in Fig. 1, thereby permitting insertion of the inner ring 14 intothe cage I6 to the position shown in Fig. 2, completing the assemblyoperation. It is apparent that the same procedure may be used in reversefor disassembly, escape of the rollers from the cage l6 when the ring 14is withdrawn from the bearing being precluded by the offsets 9 of thefingers 2|.

Cages of this general formare not new in the art and their mode ofassembly in the bearings are well understood. Novelty resides, however,in the form of the'roller-retaining offsets 9 and the manner in whichthey are produced, as hereinafter fully described.

In fabricating the cage in accordance with the invention, an annularblank 23 of solid metal is employed, see Fig. 6, having boundarydimensions suitable for finishing all over. In this blank is drilled aseries of radial holes 29, one for each of the rollers of the hearing.In the present instance the holes are drilled inwardly from the outerperipheral surface of the blank. The drill 25, shown in broken lines inFig. '7,

has" a conical end 21, andsuitable stop means (not shown) limits, thedrilling operations so that in its most advanced position the drill willoccupy a position in the cage blank, illustrated in Fig. '1, wherein theconical end 2'! will not have passed completely through the rib 24 onthe inner periphery of the blank. The metal thus'left on the sides ofthe fingers 21 at the inner ends of the bores constitutes the offsets ortangs 9 previously mentioned, and the included angle 8 of the conicalend 21 of the drill determines the taper of the conical surfaces 30 ofthe tanks. At this stage, the drilled holes 29 will appear from theoutside as shown in Fig. 8, the tangs 9 projecting into the bore of thehole at the inner end of the latter.

The cage must have rectangular pockets to accommodate the rollers, andthe next step consists of a broaching operation, or operations, whereinthe cylindrical holes formed by the drill are changed into the requiredrectangular pockets whose lengths parallel to the axis of the cageapproximates the length of the rollers, and whose widths approximate thediameter of the rollers. It will be noted, by reference to Fig. 8 thatthe width of the broach, as indicated in broken lines, is somewhat lessthan the diameter of the drill 25, so that the faces of the crossbars I8between the broached pockets exhibit recesses l' which are portions ofthe drilled holes left by the broaching operation. It will be noted alsothat the recesses 1 are wider than the fingers 21, this greater widthfunctioning for a purpose described below.

As indicated in Fig. 8, the broach is provided at each side with arecess 3| which, is wider than the fingers 2i and deeper than the radialextent of the tangs 9. These recesses are necessary in order that thebroach may clear the tangs 9 and leave them intact. The. recesses -3l,however, are of lesser width than the chord width of the recess 1 incrossbars l8, which means that when the broach is passed through theblank the edges of the recesses 3| will overlap the drilled hole and liewithin the latter, thus affording a smooth rectangular roller pocket.

In eifect the method entails the use of a drill largerthan required as apreparation for broaching to the required pocket dimensions and coned atthe end so as to leave a tang as described which projects a little wayacross an end of the pocket space; then forming a rectangular pocket bypulling through the drilled hole, a broach (one or more as required)having notches which clear the tang entirely, said broach being less inwidth than the diameter of the drill so as.

to leave depressions in the sides of the broached hole" in line with andof greater chordal width than the tangs, the teeth of the broachoverlapping the edges of the depressions to avoid burrs. Obviously, asquare'pocket, suitable for rollers whose lengths equal their diameters,would have depressions in end as well as in side walls of the pockets.

' The function of the tangs 9 has been made clear'in the descriptionabove of the mode of of outer ring I0 described above, and where theouter ring is unflanged or provided with a single internalflange similarto the flange [5 of the r" 1;: I inner ring ll of the previouslyillustrated embodiment.

We claim:

1. A one piece cage for roller bearings consisting of an annular bodymember having a circumferential series of radial rectangular pocketsintersecting the inner and outer peripheries of the said member, saidmember having also a series of fingers projecting radially from oneperiphery between the respective adjoining pairs of pockets, oppositewalls of said pockets having concaved recess extending between the outerand inner ends of the pockets and into the faces of the fingers whichconfront the pockets, said recesses terminating short of the ends of thefingers so as to leave tangs at said ends projecting into the bores ofand obstructing the proximate ends of the pockets.

2. A one piece cage according to claim 1 wherein the recesses in thewalls of the pockets are of greater width than the said fingers.

3. A one piece cage according to claim 1 wherein the said recesses inthe confronting walls of each of the pockets define a common cylinderwhich extends into the fingers adjoining said walls and terminates inconverging conical surfaces at the inner sides of the tangs at the endsor said fingers.

LOUIS R. LOVELL. JAMES E. WEST, JR.

References Cited in the file of this patent UNITED STATES PATENTS

